SwiftUI中使用结构体作为Picker元素时如何保存切换后的值？

核心问题是你当前修改的是selectedPlayer这个副本，而非playerList数组里的原始玩家实例，切换Picker后自然丢失数据。以下是具体修复步骤：

关键修改点 #

• 将playerList声明为@State变量，让SwiftUI能跟踪数组内元素的变化
• Picker绑定数组索引而非直接绑定Players实例，确保修改的是数组里的原始数据
• 移除冗余的hours状态变量，直接绑定到选中玩家的hourString

修改后的完整代码 #

import SwiftUI

struct Players: Hashable {
    var playerNumber: String
    var killString: String
    var kills: Double
    var hourString: String
    var hours: Double
}

struct ContentView: View {
    
    // 改为@State变量，允许修改数组内的元素
    @State private var playerList: [Players] = [
        Players(playerNumber: "Player 1", killString: "", kills: 0, hourString: "", hours: 0),
        Players(playerNumber: "Player 2", killString: "", kills: 0, hourString: "", hours: 0),
        Players(playerNumber: "Player 3", killString: "", kills: 0, hourString: "", hours: 0),
        Players(playerNumber: "Player 4", killString: "", kills: 0, hourString: "", hours: 0),
        Players(playerNumber: "Player 5", killString: "", kills: 0, hourString: "", hours: 0),
    ]
    
    // 绑定数组索引，而非直接绑定Players实例
    @State private var selectedPlayerIndex = 0
    
    var body: some View {
        NavigationView {
            VStack(spacing: 30){
                Group{
                    Text(playerList[selectedPlayerIndex].playerNumber)
                        .font(.system(size: 50))
                }.frame(width:350, height: 100)
                    .background(Color("AppSwag")).cornerRadius(30)
                    .foregroundColor(.white)
                Text("Select a Player")
                    .padding(10)
                Picker("Select Player", selection: $selectedPlayerIndex){
                    ForEach(playerList.indices, id: \.self) { index in
                        Text(playerList[index].playerNumber)
                    }
                }.pickerStyle(.segmented)
                
                HStack{
                    Text("Enter Players Hours:")
                    // 直接绑定到选中玩家的hourString，无需中间变量
                    TextField("", text: $playerList[selectedPlayerIndex].hourString)
                        .frame(width: 150, height: 50)
                        .background(Color.gray.opacity(0.5))
                        .cornerRadius(10)
                }
                
                HStack{
                    Text("Enter Players Kills:")
                    TextField("", text: $playerList[selectedPlayerIndex].killString)
                        .frame(width: 150, height: 50)
                        .background(Color.gray.opacity(0.5))
                        .cornerRadius(10)
                }
                Text("\(playerList[selectedPlayerIndex].playerNumber)'s values: \(playerList[selectedPlayerIndex].hourString) ")
            }// Vstack
            .navigationTitle("CSGO Calculator")
            .padding()
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

额外说明 #

• 因为结构体是值类型，直接修改selectedPlayer只会修改副本，而通过索引操作playerList里的元素，才会真正修改数据源
• 移除onSubmit是因为直接绑定TextField到数据源，输入时会实时更新，无需手动提交（如果需要提交后再更新，可以保留onSubmit，但要更新数组对应元素）

内容的提问来源于stack exchange，提问作者IMissSometimes